Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Consolidated Balance Sheets [Abstract]
Accounts and notes receivable, allowance	$ 564	$ 476
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	50,942,711	50,569,875
Common stock, shares outstanding	44,857,024	44,641,224
Treasury stock, shares	6,085,687	5,928,651